Adjustable outer jaw pipe wrench of the pivoted housing type



Feb. 24, 1953 Filed April 11,

m il

W. E. M G N ADJUSTABLE OUTER JAW PIPE WRENCH 0F THE PIVOTED HOUSING TYPE 3 Sheets-Sheet l INVENTOR. 1151/2 0714; 1667A- his 6 7' TOE/V57.-

Feb. 24, 1953 w. E. MILLIGAN 2,629,280

ADJUSTABLE OUTER JAW PIPE WRENCH OF THE PIVOTED HOUSING TYPE Filed April 11, 1950 3 Sheets-Sheet 2 INVENTOR. 11. 502 .5. (W141. IGHN.

Feb. 24, 1953 w. E. MILLIGAN 2,629,280

ADJUSTABLE OUTER JAw PIPE WRENCH OF THE PIVOTED HOUSING TYPE Filed April 11, 1950 3 Sheets-Sheet 3 IN VEN TOR. 2022 502 .(71441MM Patented Feb. 24, 1953 UNITED STATES PATENT OFFICE ADJUSTABLE OUTER JAW PIPE WRENCH OF THE PIVOTED HOUSING TYPE Wilbur E. Milligan, Boston, Mass., assignor to Walworth Company, Boston, Mass, a corporation of Massachusetts Application April 11, 1950, Serial No. 155,324

15 Claims.

large quantities despite numerous attempts over .the years to improve upon it. The spring action has been the subject of particular attention since it ensures a positive pipe gripping action together with positive release to permit the familiar ratchet movement.

The spring means is generally designed as in the aforesaid patent to hold the pivoted housing in a neutral position with the possibility of rotation of the movable jaw in either direction relative to the bar or handle. The use of two separate springs opposing each other is a common expedient but introduces the problem of adjusting the spring resistance on individual wrenches in view of normal variations in large scale manufacturing operations. Leaf springs require attachment to the bar or frame by riveting or other special operation which involves additional manufacturing expense and tends to weaken the parts. Coil springs are necessarily loosely mounted and subject to loss. Both types of spring are subject to breakage in use as they are generally exposed to damage. Under these conditions wrenches are discarded in the field as replacement of the springs is impractical.

The present invention provides a spring element positioned in the pivoted housing between the bar portion of the wrench and the shank of the movable jaw. The spring element is a generally rectangular sheet of thin flexible material having a curvature between opposite ends. The spring element has an angular end portion and a retainer section at the median portion operatively engaging a heel on the bar and a portion of the housing respectively for placing a portion of the spring element therebetween under compression. The opposite end of the spring element extends into operative engagement with the bar and acts as a cantilever. Various modified forms of the spring element are disclosed having the same general principles of spring action to provide for return of the housing and movable jaw to neutral position after pivotal movement to connect the spring element to the housing and transfer motion thereto and to provide back action or bite to the movable jaw during normal ratcheting in use.

Another object of the invention is to secure the utmost ease in action of the pivoted housing.

Another object of the invention is to regulate the force of the spring element to any desired amount.

Another object of the invention is to regulate the relationship between forward and backward action to any ratio.

Another object of the invention is to reduce wear of parts in contact with each other and to eliminate any sliding of spring sections one upon the other.

Another object of the invention is to avoid interference by the spring element with full travel of the housing and the movable jaw.

Another object of the invention is to distribute the normal stress throughout the spring element.

Another object of the invention is to retain the spring element securely in position and. protect it against damage during use of the wrench.

Another object of the invention is to eliminate machining operations and thus reduce the cost of production.

Another object of the invention is to facilitate assembly of the parts with the spring element in corrrect position without the use of tools.

Other objects and advantages will become apparent from the following description taken in connection with the accompanying drawings wherein:

Fig. 1 is a side elevation partly in section of a pipe wrench embodying the invention,

Fig. 2 is a bottom plan view of the pipe wrench shown in Fig. 1,

Fig. 3 is a partial cross-section taken on the line III-III of Fig. 1,

Fig. 4 is a perspective view of the spring element separated from the pipe wrench,

Figs. 5 to 9 inclusive are perspective views of modified forms of spring elements.

Referring more particularly to the drawings, the pipe wrench of this invention follows generally the form of that disclosed in the aforesaid Stillson patent and includes a bar It) having a handle portion I2 and a relatively stationary jaw portion [4 thereon. A movable jaw I6 is cooperable with the stationary jaw I 4 and is provided with a threaded shank l8 having the usual adjusting nut 20 positioned thereon.

A hollow housing 22 is provided for the shank V .men't 42.

The side walls of the housing22 on either side of the shank l8 are provided with oppositely disposed openings forming a window as in which the adjusting nut 20 is positioned. As shown in Fig. 1, the adjusting nut 29 is normally spaced from the lower walls 36 of the window M. Likewise, the bridge 32 is set back somewhat dram the adjacent wall 38 of the window 34. Furthermore, the bridge 32 and the bar l6 are'normally separated by aspace, designated 42, to provide :for 'freepivotal movement of the housing 22 and the movablejaw 16 relative to thestationary jaw M.

As previously indicated, this invention is more particularly directed toward improvement in'the spring action of the wrench. 'To this end, a novel spring element 42 is'provide'd and is shown more clearly in one embodiment in Fig. "i. As will be apparent, this element '22 comprises a generally rectangular sheet of thin flexible 'rnaiteri'ail provided with a pair of open-ended slots "45 extending lengthwise thereof and "terminating adjacent a median ,portionct of the spring 'ele- As 'thusconstru'cted, the slots ii, are .spacedone 'from the other fleavin'g 'twosi'de strip portions "4'8 and one middle 'strip'portion .50 connected at themedianportion 4E. The middle strip portion5ll .iorms a first bowed spring .arm section having a curvature in one direction from .the .plane of the median portion '45. The side strip portions "43 .form a pair of second bowed spring arm sections having a curvature in the opposite direction .from the plane of the median portion 415.

The apposite .end15'2 ,of the spring element 42 Iisof angular form .having normally a curvature tangential with the median portion 35. "Viewed as .a .unit therefore, the spring element -52 has a A O a curvature extending from end to end and terminates in the angular end portion '52 which .extends substantially normal to the plane of the -spring element v42. As will Lherelnafter .be apparent, the angular portion 52 is movable .lirom its tangential relation shown in 'Fig. 4 ;to the .positionshownlin fulllines in Fig. 1.

The spring ..,element $42 .is provided with a pair :of retaining .fingers '54 which project lfrom opposite sides of the median portion The re- \taining fingers :54 are .of angular .fforin having connecting portions 36 extending substantially normalto the planeof the median portion 4.5:and having outer portions 58 -:extending substantially parallel with said ,plane.

The spring element 42 sis inserted in the housing22 in the location shown-in .Fig. 1 withthe "vide a backward action.

Since the angular end portion 52 moves from the tangential position shown in broken lines in Fig. l to the full line position during the foregoing assembly operation, then the angular end portion 52 of the spring element 42 is placed under compression. This stress is relied upon for holding the spring element .42 in position in the housing 22.

The remainder of the spring element 42 functions as a two-leaf cantilever. That is, the load on the :housing'22 is applied by the bridge 32 to the :spring element 42 through the middle strip portion 50. This load is absorbed through the side "strip portions 48 on the interior of the housing 22 while the reaction at the bar 10 is absorbed by the middle strip portion 50. The

Lcombinationxofthese two deflections produces a strong backward action on the housing 22 and movable jaw it when the wrench is ratcheted forward in use. This feature is supplemental to the element of the spring action which protitles for forward -motion or which brings the movable jaw l-fi'bac'k into line after it has-overhung the stationary jaw 44. This action 'is due to the angular end portion 52 which operates against the heel 280i thebar Ill and which as previously explained is normally under stress.

It will further be observed that the spring element A2 maintains the desired neutral position of the housing 22 and movable jaw -18 due 'to'the spring sections being inequal tension while the wrench is in unoperated condition. Since the spring elernent42 'is of a unitary nature there "can ben'o variationbetween "the elements which provide a forward action and fthose which pro- -Moreover, since the spring element 42 is *housed below the window M'and within the space 4'0 between the 'bridge 32 and the bar 10, there is no interference with the full travel of the housing 22 or the :movable jaw l 5 carried "thereby. "The spring element 42 does "not become compressed :or "flattened out during use since it does not undergo any crushing taction.

In 'the modified form :of springelement "42 shown in Fig. 5;the angular portion-is bifurcated to form two arms 86 having; movement independently of each other. "Otherwise, this modified form is identical withthat shown'inl ig. 4.

-In the modified formshown in Fig."6,.a similar generally rectangular sheet of thin flexible vmaterial, as in the embodiment of 'Figs. 4 and '5, is provided for the spring element '42. However in this .modified form the cantilever ,end of ithe spring is difierent from the previously described (forms although the :spring action ,remains essentially the same. Thus, thepspring element 42 in Fig. 6 is provided with an elongated aperture .52 having aftongue 16A projecting from "the wall thereof farthest from the median portioniefi 'of'the spring element :52. The tongue .61: forms .a bowed spring arm section projecting 'fromthe plane of the median ortionffor engageim'ent ZWlth the bar I 9 at a point within the housing 22 substantially opposite .the window 34.

"The angular end portion 52 is retained in this embodimentand the tongue extends substantially parallel thereto. "The side wall portions 56 "on either side of "the aperture 62 form .a pair of neutral spring portions "having a connected end-'68 remote ijfrom the me'dianportion '46 and being "adapted to operatively engage the bridge '32 whenthe spring element 42 'is positione'd 'in the housing 22.

InFigi'Ithe cantilever end of the spring element 42 is also modified from that shown in the preceding forms. In this embodiment, the cantilever comprises a single spring arm iii comparable to the middle strip portion 58 of the Figs. 4 and 5 embodiments.

gagement with the bar I!) when the spring element 42 is in position in the housing 22. There is, however, a neutral portion 12 between the median portion 46 and the spring arm which serves to transmit forces between the spring element 42 and the bridge 32 of the housing 22. In other respects, including the angular portion 52 and the retaining fingers 58, the spring shown in the embodiment of Fig. 7 is similar to that of the preceding forms.

In the embodiments of Figs. 8 and 9, the spring element 42 follows generally the form of that described in connection with Fig. 7. The cantilever portion comprises a single spring arm 14 which is reduced in width from the neutral portion 12 and provided with an angular end I5 for operative engagement with the bar I0. Thus, the arm 14 constitutes a first bowed spring arm section projecting in one direction from the neutral portion 12 while the angular end 52 forms a second bowed spring arm section projecting in the opposite direction from the neutral portion 12. As in the preceding embodiments, the angular end portion 52 has a curvature tangential to the spring arm section of which it forms a part. A pair of retaining finger sections it project from the neutral portion 12 and are bent into spaced overlying relation. Thus, the retaining fingers have connecting portions 18 extending substantially normal to the plane of the neutral portion 12 and also have outer portions 80 extending substantially parallel to said plane. When the spring element 42 of the Fig. 8 embodiment i positioned in the housing 22, the retaining fingers T8 overlie the bridge 32 and cooperate with the angular portion 52 which operatively engages the heel 28 for compressing the angular end portion 52 of the spring element 42 therebetween.

The embodiment shown in Fig. 9 differs from that shown in Fig. 8 only insofar as the cantilever spring arm section 82 is not reduced in width from the neutral portion 12 and no angular end portion is formed thereon. Moreover, a single retaining finger B4 is provided by forming an elongated aperture 86 in the neutral portion and utilizing one wall of the aperture 86 to form a tongue projecting from the neutral portion 12. The retaining finger 34 has a connecting portion 38 extending substantially normal to the plane of the neutral portion 12 and also an outer portion 90 extending substantially parallel to said plane. It will be apparent that in both embodiments, Figs. 8 and 9, the neutral portion 12 serves to transmit forces between the spring element 42 and the bridge 32 as in the case of the embodiment shown in Fig. '7.

While various forms of cantilever spring action have been described and shown in conjunction with adjustable outer jaw wrenches of the pivoted housing type it will be apparent that various changes may be made in the details of construction and arrangement of parts without departing from the invention as defined in the appended claims.

I claim:

1. A pipe wrench comprising a bar having a handle portion and a relatively stationary jaw portion thereon, a movable jaw having a The spring arm H1 j is provided with a curvature for operative en-- threaded shank, a hollow housing for said shank pivotally mounted on said bar adjacent said stationary jaw portion and having oppositely disposed windows in side walls thereof, said side walls being connected on one side of said windows by a bridge normally spaced from said bar, said bar having a heel projecting between said ide walls on the opposite side of said windows, an adjusting nut on said shank and positioned within said housing between said windows, and a spring element positioned in said housing between the bar and said shank for normally maintaining said housing in a neutral position relative to said bar, said spring element having one end and a median portion thereof operatively engaging said heel and said one side of said windows respectively for placing :a portion of said spring element there-between under compression, said spring element extending beyond said median portion and into said space for operative engagement with said bar.

2. A pipe wrench as claimed in claim 1 wherein said one end of said spring element is of angular form for engaging said heel and is movable under compression for retaining said spring element in operative position.

3. A pipe wrench a claimed in claim 2 wherein said compressed portion of said spring element is curved longitudinally of said bar thus forming a cantilever having a free end providing said operative engagement with said bar.

4. A ipe wrench comprising a bar having a handle portion and a relatively stationary jaw portion thereon, a movable jaw having a threaded hank, a hollow housing for said shank pivotally mounted on said bar adjacent said stationary jaw portion and having oppositely disposed windows in side walls thereof, said side walls being connected on one side of said windows by a bridge normally spaced from said bar, said bar having a heel projecting between said side walls on the opposite side of said windows, an adjusting nut on said shank and positioned within said housing between said windows, and a spring element positioned in said housing between the bar and said shank for normally maintaining said housing in a neutral position relative to said bar, said spring element having an angular end portion and retaining fingers extending transversely from the median portion thereof for operative engagement with said heel and said one side of said windows respectively, said angular end portion being movable under compression for retaining said spring element in operative position, said spring element having a pair of elongated openings extending from an end 0pposite said angular end and toward said median portion and defining side and middle strip portions bowed in opposite directions respectively for operative engagement with said bar and said bridge respectively.

5. A spring element for pipe wrenches and the like comprising a sheet of flexible material having a curvature between the opposite ends thereof which lie in substantially the same plane, one of said ends terminating in a portion having angular relation to said plane and being adapted for movement relative to said sheet, a retainer section formed in said curvature and including a retaining finger section having an outer portion substantially parallel with said plane, said retainer section defining with said angular end a bowed retaining portion on said sheet adapted to be placed in compression uponsaid relative movement of said angular end, the portion of said sheet aoaaae extendin .from sa d retaine section to t e en op os te s d ng ar an o ming a .b w d prin arm seetion adapted tor cantilever action.

5. A spring element as claimed in claim 5 wherein said sheet is generally rectangular and provided with a pair of elongated openings in one end terminating adjacent said retainer .section {and defining side and middle strip portions bowed in opposite directions respectively.

7. A spri g element as claimed in claim 6' wherein said openings comprise a pair of ,open endedslotsextending lengthwise of said sheet and being spaced one from the other leaving two side a. cilo om o i strip porti ns cted at s rotain r eoiion, said-m ddl st p p ti n ormins fir t bowe s ing a m soo ioii ha n a cu vetu in d e o fr m t p an o sa d otam soo ion, said si e-strip port n f min a pai -of s ond b w d ng im s c o s havin a cunvature in the opposite direction from the plane of said retainer section, said angular end having normally a curvature tangential with said retainer section, said finger section including a pair o o o t y p ed fingers h in 1- necting portions extending substantially normal to said plane and outer portions extending substantially parallel with said plane.

,8. A spring element as claimed in claim 7 wherein said angularend is of bifurcated form.

9. A spring element as claimed in claim wherein said sheet is provided with an elongated aperture having .a tongue depending from one wall thereof and spaced from the side Wall portions, said tongue forming a bowed spring arm section .projectingfrom said plane, saidside wall portions iorminga pair of neutral portions having a c ne ted end mot f om ai r t n section, said angular ,end having normally a cu vat re t nge t a wi h sai retainer portio sa dfi eor s ct on i cludin a pa of pposi e disposed fingers having connectin portions .GX- tending substantially normal to said plane and having outer portions extending substantially parallel with said plane. 10. A spring element as defined in c1aim'9 wherein said tongue depends from the wall of said aperture opposite said connected end and substantially parallel with said angular portion.

11,. A spring element as .claimed in claim 5 wherein said retainer section includes a neutral portion, said bowed s g rm ooi p oj ctin angu ar e Port on b in rorme fr sa d utr port on. said an u a end ,Pro-

:io ting f o id neut p i n o pos t Sa oni b wed spr n a m sect nroio ne a irolsaid spr ng arm-se t o a d norma l ha n a curvature tangential thereto, said finger section projectingfrom said neutral portion and being bent into spaced overlying relation thereto.

3- ,A s ri e em a cla m d im .1 wh reinsa d re ai n in e s ct on has connecting portions o -ten su st ntia o 'ma t opposite direction from said sa d plane a d a o e ons extendin su stantially parallel to said p -lane.

14 A spring element as claimed in claim 13 wherein saidretaining finger section is of bifurcated form.

15. A spring element as claimed in claim 13' wherein said neutral portion is provided with an elongated aperture, said retaining fing r section being formed as a tongue projecting from the wall of said aperture adjacent said neutral portion.

WILBU MILL G N- BEF ERENCLES SIT-FE following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 765,912 Bordwell July-26, 1904 1,037,387 Wilkinson r Sept. 3, 1912 1,071,703 Cochran Sept. 2 1913 1,734,734 Lawson Nov. 5, 1929 1,760,54d Dickson May 27, 1930 1,862,002 Brungardt June 7, 1932 1,939,798 Thewes Dec. ;19, 1933 

